The present invention relates to a process in which surfaces of plastics are provided with electrical conductor tracks with the aid of laser beams.
Moldings made from plastics with integrated electrically conducting layers or tracks are well known, for example from the electrical and electronics industries.
Complicated cable harnesses have hitherto often been utilized for electrical supply to components bearing assemblies and used in the motor vehicle sector, for example, or in household machinery.
Another method is to attach conductor tracks to the plastics surface by hot stamping. In this process, metal foils, for example made from copper, gold or nickel, with thicknesses which are generally from 18 to 150 μm are stamped onto the plastics substrate using a heated block.
There are known processes for bonding plastics by means of laser beams (cf. Ch. Bonten in KU Kunststoffe, 89(8), pp. 33-41 (1999)).
In transmission laser welding, an adherend transparent to the laser light and an adherend which absorbs the laser light are combined and irradiated from the side of the transparent adherend. Absorption of the laser light produces heat which allows the plastics to soften in the irradiated region and thus permits welding.
In laser butt welding, laser light is used by way of a suitable optical system to irradiate at least the adherend which absorbs the laser light, preferably both adherends, and then the adherends are joined at the irradiated sites. Absorption of the laser light produces heat on the surface of the irradiated adherend(s), and this heat permits welded bonding of the two surfaces.
A review of commonly used laser welding processes may be found in the dissertation by J. Korte, “Laserschweiβen von Thermoplasten” [Laser welding of thermoplastics], University of Gesarnthochschule Paderborn, January 1998, pp, 1-8.
The processes known hitherto for producing moldings from plastic with integrated conductor tracks are very expensive and require complicated apparatus, and attempts are therefore being made to find alternative methods.
It is an object of the invention to provide a process for providing the surfaces of non-conducting plastics with electrical conductor tracks.